Sunday, February 03, 2013

February Blocking Pattern

This computer model (GFS) of near-surface temperature (actually, just above the boundary layer) and atmospheric pressure shows an interesting pattern of high and low pressure areas.  A high pressure region over the Azores is predicted to hold steady for the next several weeks, in effect blocking the normal flow of the jet stream and Eastward-migrating low pressure regions.  These lows are forced to travel (clockwise) all the way around the high pressure region.  The consequence appears to be a trough in the jet stream over Eastern  North America, leading to large incursions of Arctic air, and very, very cold temperatures (see graph).

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